(1) Field of the Invention
The present invention relates to a dialog supporting device which supports on-going dialog between people.
(2) Description of the Related Art
Conventionally, translation devices have been developed with the purpose of supporting on-going dialog in different languages, which is made between ordinary people and local people on trips abroad or the like. Such a translation device is represented by certain translation devices in which a translation scheme using original/translation pairs of example sentences, or example usages, is implemented in small information processing apparatuses such as Personal Digital Assistants (PDAs). Such devices have thousands of examples in order to cover general travel conversation. However, the devices have a problem when a user actually uses the device, since the user has to select a desired example from a list of the examples by sight. This problem is noticeable, especially when such a device has a small display for displaying the list of examples, which makes it difficult for the user to view many examples at once. Moreover, in general use of the translation device, one dialog with a dialog partner requires more than several examples, so that the translation device completes the dialog taking much more time than the user expects. Therefore, in order to achieve the final purpose of supporting dialog between people, there is a need for a function by which the user can speedily select the desired example from a great number of examples.
As a method for solving the above problem, there has been proposed a technique of narrowing down candidates for a next utterance of a user, using example dialog models or a corpus of conversation training histories, as disclosed in Japanese Unexamined Patent Application Publication No. 2003-30187, for instance.
When such a translation device is actually used, two users who speak respective different languages can have dialog using respective translation devices freely. When the translation device has an example that expresses exactly what one user wishes to say to the other user (hereinafter, referred to also as “a partner”, “a dialog partner”, or “a partner user”), the former user simply selects the example. However, each example in the translation device is generally a short sentence, so that it is able to be applied to various dialog situations. This is because a long example expresses a rather specific situation and thereby applications of the sentence are considerably limited. Therefore, the user has to express what to say, by sequentially selecting a plurality of such short examples.
However, although it is possible to shorten a time required to select examples using, for instance, the technique disclosed in the above-mentioned Japanese Unexamined Patent Application Publication No. 2003-30187, or the like, it is not possible to completely eliminate a time lag between selection of a certain example and selection of a next example. Therefore, as explained below, depending on how the translation device is used, there is a problem that one utterance is outputted from the translation device, using operations which are several times as many as operations for searching one example.
For instance, it is assumed that a user A who speaks Japanese has a dialog with a user B who speaks English, and that the user A wishes to say to the user B, “I'd like to know a cheap way to get to the airport”. In this situation, a translation device of the user A has only the following examples which are related to what the user wishes to say.
<Example 1> “ ” “How can I get to the airport?”
<Example 2> “” “I'd like to take a cheaper way.”
Here, the user A firstly selects “ ” and then selects “”. The user B hears the example 1 “How can I get to the airport?” outputted from a translation device of the user B, and then, after a certain time period, hears the example 2 “I'd like to take a cheaper way”. Here, it is assumed that the user B attempts to reply to the user A immediately after hearing the example 1, and thereby searching for examples explaining ways to an airport using the translation device of the user B. When the user B hears the example 2 from the user A during the above searching, the user B has to delete all of the searching operations, and begins to search for different examples to reply to the example 2. In short, although the conventional technologies reduce example searching operations required to output one utterance, a problem still remains that the outputting is often cancelled by interruption of a partner's further utterance, so that the operations for the unnecessary outputting are wasted operations. As a result, depending on how the translation device is used, outputting of one utterance from the translation device requires a great number of operations which are several times as many as the operations required to search for one example.
Thus, in view of the above problems, an object of the present invention is to provide a dialog supporting device which can support dialog to be speedily completed on the whole, by reducing the number of operations for generating one utterance regardless of partner's interrupting utterances.